Bone crusher

Bones obtained during slaughter are cleaned, boiled in water and dried for several months.

After that, they are suitable for crushing with the special machine into a relatively dry gritty powder which is used as fertilizer.

[citation needed] The machine, shown in the picture, is powered by a water wheel.

It contains eight S-shaped pairs of cams that raise the crushers alternately and let them fall into material to be crushed.

Bone meal has been used since about 1790 as a fertilizer supplement to ordinary farmyard manure.